For example, the median serum infliximab concentration at week 8 in clinical responders was 35.0 μg/mL compared with 25.8 μg/mL in clinical nonresponders for the 5-mg/kg group at week 8. Similar results were observed selleck for clinical response and mucosal healing during maintenance at week 30 and week 54 (Table 1). For example, in patients who received the 5-mg/kg regimen, the median trough serum infliximab concentration

in clinical responders was several-fold that of clinical nonresponders (eg, 3.9 vs 1.2 μg/mL at week 30 and 5.0 vs 0.7 μg/mL at week 54, respectively). With respect to clinical remission among patients in the 5-mg/kg group, the median serum infliximab concentration at week 8 was not significantly higher in week-8 remitters than in nonremitters (35.1 vs 30.8 μg/mL; P = .097). By comparison, the difference in serum infliximab concentrations between remitters and nonremitters at week 8 was statistically significant for the 10-mg/kg dose group (P = .0002) ( Table 1). The median

serum infliximab concentration was significantly higher in remitters than Dasatinib nonremitters at week 30 (P < .0001) and week 54 (P < .005), regardless of infliximab dose ( Table 1). Although median serum infliximab concentrations were consistently higher in patients with positive efficacy outcomes than those who failed to achieve these outcomes, there was some overlap of the distribution of serum infliximab concentrations between these groups. The overlap, however, was greater during induction at week 8, but less prominent during maintenance at week 30 or week 54. It also appears that there was more variability of serum infliximab concentrations in patients P-type ATPase who failed to respond during maintenance

(Figure 3). When assessed by infliximab concentration quartiles, the proportions of patients with treatment success as defined by multiple outcome measures (ie, clinical response, mucosal healing, and/or clinical remission) generally increased with increasing infliximab concentration for the 5-mg/kg dose regimen. In each case, a significantly positive association was observed for the relationship between serum infliximab concentration quartiles and clinical outcomes (Supplementary Figure 3). Patients with serum infliximab concentrations in the lowest quartile consistently were less likely to show clinical response, clinical remission, or mucosal healing and had rates of success approaching those observed in patients assigned to placebo.2 Notably, this finding was still evident when the quartiles were examined for the 10-mg/kg dose regimen, as illustrated for the end point of clinical response in Supplementary Figure 4.